The objective of this contract is to provide on-site research support in inhalation toxicology for the National Toxicology Program and for other research components in the National Institute of Environmental Health Sciences, (NIEHS). This contract provides for the complete operation of a government owned inhalation facility located on the North Campus of the NIEHS. The contract requires both operating the exposure facility and conducting animal research on the inhalation toxicology of environmental chemicals. Specific studies are designed by government researchers and presented as research protocols to be executed by the contractor. The contract provides for the measurements of a variety of experimental end points and for the delivery treated animals and biological samples to researchers at the NIEHS.